/Engine/Source/Runtime/UMG/Public/Blueprint/UserWidget.h
Called when the mouse wheel is spun. This event is bubbled.
Returns whether the event was handled, along with other possible actions
[FEventReply](API\Runtime\UMG\Components\FEventReply) OnMouseWheel ( [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) MyGeometry, const [FPointerEvent](API\Runtime\SlateCore\Input\FPointerEvent) & MouseEvent )